Clinical applications of transcutaneous catheters include, for example, suprapubic bladder drainage, transcutaneous and intrathoracic access to central venous vessels, peritoneal dialysis, and intravascular access for chemotherapy, among others. Use of transcutaneous catheters in these treatments permit skin microbes to adhere to catheter surfaces to migrate along the catheter. The microbes then may enter the body by adhering, replicating and migrating within biofilms into intra-corporeal organs.
In the case of suprapubic bladder drainage, in particular, the urinary bladder is a hollow spherical muscle that serves as a muscular reservoir to hold about 8-12 ounces of urine. A sphincter muscle at the bladder outlet normally closes around the urethra to allow the bladder to fill with and retain urine. During filling, the bladder is relaxed and the sphincter muscle is contracted. The nervous system normally alerts the brain when the bladder is near full, triggering an urge to expel the urine contents of the bladder. During normal urination, the brain triggers pelvic nerves that cause the bladder muscle to contract and the sphincter muscle to relax in coordinated manner. Urine is then expelled from the bladder through the urethra.
Neurological damage, and other maladies, can impair contraction and coordination of the bladder and sphincter muscles. Loss of bladder control can result in incontinence. Spinal cord injury (SCI) is a non-exclusive example instance in which neurological damage may disrupt or impair normal operation of the urinary bladder. Most SCI patients can have chronic urinary retention. Some have incontinence and/or a combination of chronic retention with episodic incontinence. A high percentage of SCI patients use intermittent catheterization, Foley urethral catheter drainage, and/or suprapubic bladder drainage methods to evacuate the bladder on a chronic basis.
Foley and suprapubic bladder drainage are open access, meaning that skin microbes have constant access to external surfaces of these chronic, indwelling, drainage tubes Skin microbes adhere to external catheter surfaces. As microbes replicate, they migrate (mostly) along the exterior catheter surfaces and thereby gain access to the bladder lumen. The external catheter surface is constantly moistened with urine or urethral mucous or both. About 100% of SCI patients utilizing Foley urethral or suprapubic tube drainage for (on the order of) about >60 days have microbial colonized urine. Existing antimicrobial-coated tubes or systemic antibiotics can reduce the colonization rate, for example, from approximately 5%/day to approximately 2-3%/day. This prophylactic use of antimicrobial agents invites colonization by antibiotic resistant microbes.
Bacteria have two life-styles, planktonic (i.e., floating) or sessile (i.e., attached to a surface). Urinary pathogens typically have sugar molecules on their surface causing them to adhere to catheter surfaces where they may multiply rapidly. Concentrations of adherent microbes may frequently exceed on the order of about 106/ml in 24 hours and 107/ml in 48 hours. Microbial metabolism changes in these sessile, dense microbial colonies. This phenomenon is called quorum signaling. Quorum signaling creates microbial biofilms which are slimy mixtures of peptides, amino acids, proteoglycans, and cellular and microbial debris. The biofilm acts as a sanctuary. Microbes trapped within the biofilm may be, for example, on the order of about 1000×-10,000× more resistant to traditional antibiotics than are planktonic microbes.
Thus, SCI patients and others that utilize traditional, chronic, indwelling Foley urethral catheters and suprapubic tubes are subject to constant access of skin microbes to external surfaces of urethral catheters. Resident skin microbes adhere, multiply explosively, and migrate as dense colonies along the catheters primarily on the external surface into the bladder lumen. These migrating bacteria form biofilms on catheter surfaces that harbor and perpetuate microbial growth and increase resistance to antimicrobial agents. Antibiotics can sterilize urine by killing planktonic bacteria but have little or no effect on biofilm embedded organisms on the catheter surfaces. Thus, continuous access of skin microbes to catheter surfaces cause Catheter-Associated Urinary Tract Infection [CAUTI] which is widely recognized as a major chronic problem increasing morbidity rates.
It would therefore be desirable, and a significant improvement in the art and technology, to provide systems, devices and methods for transcutaneous catheter treatment, including for bladder drainage, on a long term basis, which systems, devices and methods prevent or reduce bacterial incursion, adhesion, and/or formation of biofilms.